I've been staying out of this until now, but I would like to point out that wk057's information from the BMS is correct. Each car's BMS is constantly calculating it's real capacity and it's visible right there in the diagnostic screen.
This is also why Tesla does not (willingly) give us access to this information.
Also, if you compare packs across the cars, you quickly see that none of them have identical capacity. Due to manufacturing tolerances, each of the cells ends up with slightly more or less amp-hour capacities. Due to the intelligent design of the packs this generally averages out pretty nicely, so the actual difference in practice is small, and quickly is lost in the noise of how the pack is treated under use. However, if owners had access to this data, people would be constantly up in arms when comparing cars. It's also true that as time goes on the cells being manufactured get better and have more capacity. So an early "90" pack usually had noticeably less capacity when new than it's more recently manufactured versions. It doesn't feel good when you find out you got one of the "duds".
On top of all this they are also introducing other things most people have no idea about, for instance the newer versions of some packs have significantly more output current capability than earlier ones. This has a great impact on performance. Tesla doesn't tell us about this.
They are also taking away output current after too many launches on some packs. So if you do too many launches, you may suddenly find your car's performance reduced, with no indication from the car or Tesla, and no advance notice that this could happen. This is shady dishonest behavior in my opinion.
Don't ask me for specific data, I'm not going to give it. I just want to point out that I Love Tesla, and support their mission, but I think this is not the right way to do things. It's fine if they want to impose a launch limit, but they need to INFORM owners of this!
I also believe it's fine to round the numbers on capacity a bit, as well as have the bottom discharge buffer. Most ICE cars don't let you use all the fuel in the tank either, they mount the intake tube off the bottom a bit to avoid sucking in the sediment that ends up there. Totally OK. What's not ok is using this "fudge factor" for marketing wank. They should have been consistent with the software limited 60. Also, they should call the models "65, 75, 90, etc" but leave off the kWh designation. In the official specs, maybe in fine print, state the approximate usable kWh for those of us that expect numbers not to lie. Right there on the front of all packs is a label proudly stating a kWh capacity value that it can never achieve.
Tesla has some amazing engineering and has managed to succeed against crazy odds. Trust is already thin though. It would be an awesome change for a large company to buck the trend and start being honest with it's customers and begin building an organization we can all TRUST. The value of that in the future will be worth billions. Stop with the dishonest fabricated stats, stop permitting employees in the service centers from lying to customers. INTEGRITY will be a welcome change. Instead I am saddened to see all the Tesla has built thus far slowly sliding down in to the slimy muck territory that we experience while owning other brands. Tesla's ownership experience has convinced me to avoid doing business with them in the future (unless something changes). I love the cars, and own/have owned quite a few, but I am now only buying them salvage after Tesla has disowned them. I have only ever purchased one new from Tesla, and it was such a poor experience overall, I don't think I will consider it ever again until they clean up their act.
I believe the success of Tesla's mission is in jeopardy if they don't make some changes now. It would be sad to see all this come crumbling down.
Fix customer communication.
Fix the service experience.
Make service software, information, and parts available to all owners.
A true mass market success depends on this!
This is also why Tesla does not (willingly) give us access to this information.
Also, if you compare packs across the cars, you quickly see that none of them have identical capacity. Due to manufacturing tolerances, each of the cells ends up with slightly more or less amp-hour capacities. Due to the intelligent design of the packs this generally averages out pretty nicely, so the actual difference in practice is small, and quickly is lost in the noise of how the pack is treated under use. However, if owners had access to this data, people would be constantly up in arms when comparing cars. It's also true that as time goes on the cells being manufactured get better and have more capacity. So an early "90" pack usually had noticeably less capacity when new than it's more recently manufactured versions. It doesn't feel good when you find out you got one of the "duds".
On top of all this they are also introducing other things most people have no idea about, for instance the newer versions of some packs have significantly more output current capability than earlier ones. This has a great impact on performance. Tesla doesn't tell us about this.
They are also taking away output current after too many launches on some packs. So if you do too many launches, you may suddenly find your car's performance reduced, with no indication from the car or Tesla, and no advance notice that this could happen. This is shady dishonest behavior in my opinion.
Don't ask me for specific data, I'm not going to give it. I just want to point out that I Love Tesla, and support their mission, but I think this is not the right way to do things. It's fine if they want to impose a launch limit, but they need to INFORM owners of this!
I also believe it's fine to round the numbers on capacity a bit, as well as have the bottom discharge buffer. Most ICE cars don't let you use all the fuel in the tank either, they mount the intake tube off the bottom a bit to avoid sucking in the sediment that ends up there. Totally OK. What's not ok is using this "fudge factor" for marketing wank. They should have been consistent with the software limited 60. Also, they should call the models "65, 75, 90, etc" but leave off the kWh designation. In the official specs, maybe in fine print, state the approximate usable kWh for those of us that expect numbers not to lie. Right there on the front of all packs is a label proudly stating a kWh capacity value that it can never achieve.
Tesla has some amazing engineering and has managed to succeed against crazy odds. Trust is already thin though. It would be an awesome change for a large company to buck the trend and start being honest with it's customers and begin building an organization we can all TRUST. The value of that in the future will be worth billions. Stop with the dishonest fabricated stats, stop permitting employees in the service centers from lying to customers. INTEGRITY will be a welcome change. Instead I am saddened to see all the Tesla has built thus far slowly sliding down in to the slimy muck territory that we experience while owning other brands. Tesla's ownership experience has convinced me to avoid doing business with them in the future (unless something changes). I love the cars, and own/have owned quite a few, but I am now only buying them salvage after Tesla has disowned them. I have only ever purchased one new from Tesla, and it was such a poor experience overall, I don't think I will consider it ever again until they clean up their act.
I believe the success of Tesla's mission is in jeopardy if they don't make some changes now. It would be sad to see all this come crumbling down.
Fix customer communication.
Fix the service experience.
Make service software, information, and parts available to all owners.
A true mass market success depends on this!
